Boring-tool



A. E. CLAUDON.

BORING TOOL.

APPLICATION FILED APR.12, 191a.

Patented Nov. 23, 1920.

4== INVENTOR A E CLAUDON.

@W TTORNEY names stares rarest QEFEQE AUGUSTE E. CLAUDON, DENVER, COLORADO.

BORING-TOOL.

for cutting large holes in metal plates around smaller holes previously made for the guidance of the tool.

' It is the primary object of the present in-.

.vention to provide a boring tool of the character mentioned which has certain features of construction by which its cutting action is facilitated and its strength and durability materially increased.

My improved tool is particularly adapted for boring holes in the flue sheets of boilers and with this in view it has in addition to the features of construction hereinabove referred to, 'a novel means for chamfering the edges'of the holes for the purposes of preventing injury to the fines expanded therein and of providing a recess for the reception of the beads produced by upsetting the ends of the fines.

An embodiment of my invention is shown in the accompanying drawlngs inwhich similar characters of reference deslgnate corresponding parts throughout the several views and in which- Figure 1 represents a partially sectional slde elevation of my improved boring tool,

' Fig. 2, an end view of the same looking in the direction of the arrow A, Fig. .1,

Fig. 3. a face view of one of the cutters or bits of the tool drawn to an exaggerated scale,

Fig. 4 an edge view of the same looking in the direction of the arrow B, Fig. 3, r

Fig. 5, a .top view of the bit or cutter shown in Fig. 3, and

Fig. 6, a section taken along the line 6-6, Fig. 5.

In the drawings the reference character 2 designates the stock which holds the bits of cutting tools and which has. a tapering shank 3 for its connection with a boring machine of conventional construction.

Specification of Letters Patent.

Patented Nov. 23, 1920.

Application filed April 12, 1918. Serial No. 228,130.

The head 4 of the stock has diametrically opposite longitudinal channels 5 for the reception of the bits hereinafter to be described, and a central tapering socket with in which is fitted the forwardly projecting rose-reamer 6 which in the operation enters the hole previously made in the metal plate and serves as a pilot and a support for the cutting tool proper. r

The head of the stock has in alinement with the edges of its channels, rearward with relation to the direction of rotation,

forwardly projecting bosses 7 which support the backs of the portions of the bits projecting from the channels and prevent thendisplacement or breakage when they are driven through the metal by rotation of the stock.

An annular flange 8 on the stock back of its head carries two adjusting screws 9 which engage the ends of the bits supported in the channels andprovide a ready means to aline the cutting edges at the opposite ends of the same. j

- A collar 10 surrounding the head of the stock provides a support for set screws 12 which by engagement with the outer faces of the bits secure them in their adjusted positions. V V

The bits which in the operation of the tool, bore a hole in a-metal plate by cutting an annular channel around the previously made smaller hole through which the reamer 6 extends. have been shown indetail in Figs.

3 to 6 of the drawings. I

It is in the construction of these bits that the more important improvements of my invention reside, and I desire it understood thatwhile the improved bits are particularly adapted for use in a stock of the construction shown and herein described, they may be employed in connection with holders ofdifl'erent de'sign'within the scope of my invention.

The bits which are formed on a lathe by means of a specially constructed mandrel,

. have a cutting blade'13 of curved and tapering section, at the end of a shank 14 of rectangular section which fits within the channels of the bit stock.

The outer face 15 the cutting blade of curved in the arc of a circle eccentric to that of the outer face. 7

e As a result of this arrangement of ts curved sides, the cutting blade of the bit diminishes gradually in thickness from its forward cutting edge 17 rearward to provide a clearance in the direction ofits cir- (1111a; movement, and its outer face rests evenly upon the surface of the hole pro duced by the cutting action of the tool.

The end of the blade is beveled toward the edge 17 and a transverse groove 18 cut in said edge adjoining its beveled end, provides a cutting lip 19'of acute angular form and immediately rearward thereof, a passage through which the cuttings may freely 'move out of the hole produced by the operation of the tool.

By reducing the part of the blade adjoining the shank, in thickness, a cutting head20 is formed which in the operat on of the tool cuts into the metal and provides a clearance by which the major portion of the blade is permitted to move freely into and through the opening produced by action of the bits.

All undue friction between the cutting blades of the tool and the metal is thus eliminated and the possibilities of breaking or bending the bits within the hole, are reduced to the minimum.

, The cutting blade of each bit is offset with relation to the axis of its'shank to provide at itsjuncture with the shank, a rounded shoulder 22, and the'shank is grooved immediately beneath this shoulder as shown at 23 in Figs. 3 and 4, to form a cutting edge era the end of the shoulder corresponding with the forward edge 17 of the cutting blade 13. The cutting edges 2 1 of the bits in the "boring-tool engage the edge of the hole produced by the cuttingblades of thesame and thereby produce a chamfer which prevents injury to the flue expanded in the hole and at the same time provides a recess around the hole to admit the bead formed by upsetting the end of the flue for the purpose of securing it in air-tight connectionwith the "sheet in which the holeis bored.

In the operation of my improved tool the reamer 6 is inserted in one of a series of holes which are punched in the flue-sheet before its being bored. I 7

The bits which are alined by adjustment of the screws, bite with their sharp-edged lips into the metal of the sheet and cut a circular groove around the hole through which a reamer extends.

The cuttings move out of the groove through the passages 18 of the bits without in any way interfering with the cutting action, and the tapering form of the cuttlng heads together with the reduced width of the necks by which they are connected with their respective shanks, give ample clearance to prevent binding and to avoid all undue friction during the combinedrotary and longitudinal movements of the tool. 7 ,7 After the hole is completed the front edge thereof is countersunk by the action of the cutting edges at the j unctures of the cutting blades of the bits with their respective shanks for the purposes hereinbefore explained. 7

Having thus describedmy invention what I claim and desire to secure Zby Letters Patcut is: V

1. In a boring tool,a head, a-central guide projecting beyond the head, and 'a bit carried by thehead radially beyond said guide, said bit having ahshank and a'blade'eXtend- Hing-from the shank, said blade being -.re-

duced on its inner andouter sides to provide clearances, said inner-and outer sides being curved, shoulders formed between the shank and reduced inner and outer sides of said blade, and a cutting edge formed at theend of one of said shoulders.

2. In a boring tool, a head, a central guide carried by said head, and abit fitted in said head radially beyond said guide, said bit composed of a shank and a blade, said blade having its inner and outer sides reduced forming shoulders withthe shank and clearance spaces beyondtheshoulders, the outer reduced side of the blade being curved on the same center with said guide,

the inner side curved eccentric to the curvature of the outer side whereby the blade tapers from the front to the rear with respect to its direction of rotation, one of said shoulders 'b'eing curved,-and a cutting edge formed at the end of said curved shoulder.

being beveledand the blade notched adjacent the beveled edge to provide a passage for the borings, shoulders at the base of the blade, and an inclined cutting edge at the end of one of the shoulders.

4. In a device of the class described a bit comprising a shank, a cutting blade integral therewith, same .being curved and tapered toward one side edge, a cutting head formed at the outer end of said blade, the tapering of said blade affording clearance spaces between said head and the shank, the outer vide a shoulder therebetween, one end of free edge of the blade being beveled and said shoulder being provided with a cutsaid blade notched adjacent the beveled edge ting edge, and acutting head formed on' 10 to provide a passage for the boring. said shank.

5 5. In a device of the class described, a In testimony whereof I have afiixed my bit comprising a shank, a cutting blade signature. formed integral'therewith and ofi'set to pro- AUGUSTE E. CLAUDON. 

